Open Collections

Cyr, Elsa

University of British Columbia

Insects possess gustatory receptor neurons that respond to different taste modalities. These neurons express receptor proteins that are tuned to specific taste molecules to elicit a response in the neuron. Taste processing has been extensively studied in Drosophila melanogaster, which makes it an ideal model to identify molecular mechanisms conserved in other insects. In this study, we explore the neural basis of taste processing in the yellow fever mosquito, Aedes aegypti which utilizes its gustatory system to detect non-volatile chemosensory cues during behaviours such as blood feeding, nectar feeding, and egg laying. We hypothesize that taste processing mechanisms in A. aegypti are broadly conserved with D. melanogaster, but that mosquito-specific adaptations have evolved to support mosquito-specific behaviours. To test this, I produced a comprehensive anatomical and functional characterization of gustatory receptor neurons expressing taste receptors in the tarsi of mosquitoes. I used genetic driver lines to label sensory neurons, characterizing their anatomy and neural activity in response to taste stimuli. To investigate the anatomical map, I examined four different populations of neurons across all three legs in males and females. I found that specific populations of neurons are distributed throughout the legs, and across sexes in accordance with the behaviours they are associated with. To investigate the functional characterization of the neurons, I developed a novel protocol for live cell imaging in the tarsus during liquid tastant delivery. With this setup, I explored whether, similarly to D. melanogaster, neurons in the mosquito are broadly tuned to appetitive tastants, with overlapping populations of neurons responding to various appetitive taste molecules. I specifically tested sucrose, associated with mosquito nectar feeding behaviour, and lactic acid or low concentrations of sodium chloride, associated with blood feeding behaviour. My results show that non-overlapping populations of neurons in the mosquito respond to the appetitive tastants tested. These results are not consistent with observations in D. melanogaster but support the duality of the feeding systems in mosquitoes. Overall, this work aims to provide a better understanding of the neural coding of mosquito gustation for better understanding of the molecular basis of various key behaviour in mosquitoes.

Text

2024-02-06

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87413

Zoology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/